1 12-Bit R/D Converter with Reference Oscillator AD2S1200 . FEATURES GENERAL DESCRIPTION. Complete monolithic R/D Converter The AD2S1200 is a complete 12-Bit resolution tracking resolver- Parallel and serial 12-Bit data ports to-digital Converter , integrating an on-board programmable System fault detection sinusoidal oscillator that provides sine wave excitation for Absolute position and velocity outputs resolvers. An external MHz crystal is required to provide Differential inputs a precision time Reference . This clock is internally divided to 11 arc minutes of accuracy generate a MHz clock to drive all the peripherals. 1,000 rps maximum tracking rate, 12-Bit resolution The Converter accepts V p-p 10% input signals, in the Incremental encoder emulation (1,024 pulses/rev). range of 10 kHz to 20 kHz on the Sin and Cos inputs. A Type II. Programmable sinusoidal oscillator on-board servo loop is employed to track the inputs and convert the input Compatible with DSP and SPI interface standards Sin and Cos information into a digital representation of the kHz square wave output input angle and velocity.
2 The bandwidth of the Converter is set Single-supply operation ( V 5%). internally to kHz with an external MHz crystal. The 40 C to +125 C temperature rating maximum tracking rate is 1,000 rps. 44-lead LQFP package 4 kV ESD protection FUNCTIONAL BLOCK DIAGRAM. CLKIN. REFBYP REFOUT FS1 FS2 XTALOUT ( ). INTERNAL. AD2S1200 VOLTAGE ( ) CLOCK. Reference GENERATOR. EXC Reference . OSCILLATOR ( ). EXC (DAC). CLOCK CPO. DIVIDER. SYNTHETIC DOS. Reference FAULT. INDICATORS. SinLO LOT. ADC. Sin MONITOR MONITOR. ERROR. CALCULATION/. ANGLE SIGNAL ERROR DEMODULATOR. ERROR. CosLO MONITOR. ADC. Cos DIGITAL. FILTER. ANGLE . A. ENCODER POSITION VELOCITY. EMULATION INTEGRATOR DIR. B INTEGRATOR. NM. POSITION REGISTER VELOCITY REGISTER. SAMPLE. MULTIPLEXER. CS. DATA BUS OUTPUT. RD. 04406-0-001. RESET RDVEL SOE DB11 DB10 DB9 DB0. SO SCLK. Figure 1. Rev. 0. Information furnished by Analog Devices is believed to be accurate and reliable.
3 However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication One Technology Way, Box 9106, Norwood, MA 02062-9106, or otherwise under any patent or patent rights of Analog Devices. Trademarks and Tel: registered trademarks are the property of their respective owners. Fax: 2003 Analog Devices, Inc. All rights reserved. AD2S1200 . APPLICATIONS Triple Format Position Data: Absolute 12-Bit angular Electric power steering binary position data accessed either via a 12-Bit parallel Electric vehicles port or via a 3-wire serial interface. Incremental encoder Integrated starter generator/alternator emulation in standard A QUAD B format, with direction Encoder emulation output is available.
4 Automotive motion sensing and control Digital Velocity Output: 12-Bit signed digital velocity, twos complement format, accessed either via a 12-Bit PRODUCT HIGHLIGHTS parallel port or via a 3-wire serial interface. Complete Resolver-to-Digital Interface: The AD2S1200 . provides the complete solution for digitizing resolver Programmable Excitation Frequency: Excitation fre- signals ( 12-Bit resolution) with on-board programmable quency easily programmable to 10 kHz, 12 kHz, 15 kHz, or sinusoidal oscillator. 20 kHz by using the frequency select pins. Ratiometric Tracking Conversion: This technique System Fault Detection: A fault detection circuit will provides continuous output position data without detect any loss of resolver signals, out of range input conversion delay. It also provides noise immunity and signals, input signal mismatch, or loss of position tracking.
5 Tolerance of harmonic distortion on the Reference and input signals. Rev. 0 | Page 2 of 24. AD2S1200 . TABLE OF CONTENTS. AD2S1200 Specifications ..4 Incremental Encoder Absolute Maximum Ratings ..6 On-Board Programmable Sinusoidal ESD Caution ..6 Supply Sequencing and Pin Configuration and Function Descriptions ..7 Charge Pump Output ..17. Resolver Format Signals ..8 Circuit Dynamics ..18. Principle of AD2S1200 Loop Response Model ..18. Fault Detection Sources of Error ..19. Connecting the Converter ..11 Clock Requirements ..20. Absolute Position and Velocity Output ..12 Connecting to the Parallel Outline Serial Ordering Guide ..21. REVISION HISTORY. Revision 0: Initial Version Rev. 0 | Page 3 of 24. AD2S1200 . AD2S1200 SPECIFICATIONS. Table 1. (AVDD = DVDD = V 5% @ 40 C to +125 C CLKIN MHz, unless otherwise noted.). Parameter Min Typ Max Unit Conditions/Comments Sin, Cos INPUTS1.
6 Voltage V p-p Sinusoidal waveforms, differential inputs Input Bias Current 2 A VIN = V p-p Input Impedance M VIN = V p-p Common Mode Volts 100 mV Peak CMV @ SinLO, CosLO, with respect to REFOUT @ 10 kHz Phase Lock Range 45 +45 Degrees Sin/Cos vs. EXC output ANGULAR ACCURACY. Angular Accuracy 11 arc min Zero acceleration Y Grade 22 arc min Zero acceleration W Grade Resolution 12 Bits Guaranteed no missing codes Linearity INL 2 LSB Zero acceleration, 0 to 1,000 rps Linearity DNL LSB Guaranteed monotonic Repeatability 1 LSB. Hysteresis 1 LSB. VELOCITY OUTPUT. Velocity Accuracy 2 LSB Zero acceleration Resolution 11 Bits Linearity 1 LSB Guaranteed by design 2 LSB max Offset 0 1 LSB Zero acceleration Dynamic Ripple 1 LSB Zero acceleration DYNAMIC PERFORMANCE. Bandwidth 1,500 1,700 2,000 Hz Fixed Tracking Rate 1,000 rps Guaranteed by design.
7 Tested to 800 rps. Acceleration Error 30 arc min At 10,000 rps2. Settling Time 179 Step Input ms To within stated accuracy Settling Time 179 Step Input ms To within one degree EXC, EXC OUTPUTS. Voltage V p-p Load 100 A. Center Voltage V. Frequency 10 kHz FS1 = high, FS2 = high 12 kHz FS1 = high, FS2 = low 15 kHz FS1 = low, FS2 = high 20 kHz FS1 = low, FS2 = low EXC/EXC DC Mismatch 35 mV. THD 60 55 dB First five harmonics FAULT DETECTION BLOCK. LOS. Sin/Cos Threshold V p-p DOS and LOT go low when Sin or Cos fall below threshold. Angular Accuracy (Worst Case) 45 Degrees LOS indicated before angular output error exceeds limit ( V p-p input signal and V LOS threshold). Angular Latency (Worst Case) 90 Degrees Maximum electrical rotation before LOS is indicated ( V p-p input signal and V LOS threshold). Time Latency 125 s 1. The voltages Sin, SinLO, Cos, and CosLO relative to AGND must always be between V and AVDD.
8 Rev. 0 | Page 4 of 24. AD2S1200 . Parameter Min Typ Max Unit Conditions/Comments FAULT DETECTION BLOCK (CONT.). DOS. Sin/Cos Threshold V p-p DOS goes low when Sin or Cos exceeds threshold. Sin/Cos Mismatch 385 420 mV DOS latched low when Sin/Cos amplitude mismatch exceeds the threshold. Angular Accuracy (Worst Case) 30 Degrees DOS indicated before angular output error exceeds limit. Angular Latency (Worst Case) 60 Degrees Maximum electrical rotation before DOS is indicated. Time Latency 125 s LOT. Tracking Threshold 5 Degrees LOT goes low when internal error signal exceeds threshold. Guaranteed by design. Time Latency ms Hysteresis 4 Degrees Guaranteed by design VOLTAGE Reference . REFOUT V IOUT = 100 A. Drift 70 ppm/ C. PSRR 60 dB. CHARGE PUMP OUTPUT (CPO). Frequency kHz Square wave output Duty Cycle 50 %. POWER SUPPLY. IDD Dynamic 18 mA.
9 ELECTRICAL CHARACTERISTICS. VIL Voltage Input Low V. VIH Voltage Input High V. VOL Voltage Output Low V 2 mA load VOH Voltage Output High V 1 mA load IIL Low Level Input Current 10 A. IIH High Level Input Current 10 A. IOZH High Level Three-State Leakage 10 A. IOZL Low Level Three-State Leakage 10 A. Rev. 0 | Page 5 of 24. AD2S1200 . ABSOLUTE MAXIMUM RATINGS. Table 2. Stresses above those listed under Absolute Maximum Ratings Parameter Rating may cause permanent damage to the device. This is a stress Supply Voltage (VDD) V to + V rating only; functional operation of the device at these or any Supply Voltage (AVDD) V to + V other conditions above those indicated in the operational Input Voltage V to VDD + V sections of this specification is not implied. Exposure to Output Voltage Swing V to VDD + V absolute maximum ratings for extended periods may affect Operating Temperature Range (Ambient) 40 C to +125 C device reliability.
10 Storage Temperature Range 65 C to +150 C. Lead Temperature Soldering Vapor Phase (60 sec) 215 C. Infrared (15 sec) 220 C. ESD CAUTION. ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although this product features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality. Rev. 0 | Page 6 of 24. AD2S1200 . PIN CONFIGURATION AND FUNCTION DESCRIPTIONS. REFOUT. REFBYP. CosLO. SinLO. AGND. AGND. AVDD. EXC. EXC. Cos Sin 44 43 42 41 40 39 38 37 36 35 34. DVDD 1 33 RESET. RD 2 32 FS2. CS 3 31 FS1. SAMPLE 4 30 LOT. RDVEL 5 AD2S1200 29 DOS. SOE 6 TOP VIEW 28 DIR.